Folding bed counterbalance mechanism



Jan. 29, 1957 Filed Feb. 16, 1955 w. VAN DER SLUYS 2,779,032

FOLDING BED COUNTERBALANCE MECHANISM 4 Shets-Sheet 1 52mm .H- II Jkvem 02".

Jan. 29, 1957 W. VAN DER SLUYS FOLDING BED COUNTERBALANCE MECHANISM Filed Feb. 16, 1953 4 Sheets-Sheet 2 Jan. 29, 1957 w. VAN DER SLUYS 2,779,032

FOLDING BED COUNTERBALANCE MECHANISM.

Filed Feb. 16, 1953 4 Sheets-Sheet 3 Jan. 29, 1957 w. VAN DER SLUYS 2,779,032

FOLDING COUNTERBALANCE MECHANISM Filed Feb. 16, 1953 4 Sheets-Sheet 4 l III III |I||||||| IIIMH f 1% 1 L IIU UMIII I H III 1 mm ll l United States PatentO FOLDING BED COUNTERBALANCE MECHANISM William Van Der Sluys, Homewood, lll., assignor to Pullman-Standard Car Manufacturing Company, Chicago, 11]., a corporation of Delaware Application February 16, 1953, Serial No. 336,971

Claims. (Cl. 5164) The present invention relates to a spring counterbalance mechanism for a folding bed, and more particularly to mechanism incorporating a torsion spring for counterbalancing an endwise foldable railway car bed.

The invention is illustrated as employed in connection with a folding, that is, pivoted, bed in a railway sleeping car, although it is adapted for use with similar beds in other environments and with other pivoted devices in many fields, such for example as doors, ladders or steps, and the like. Axially alined helical torsion springs are mounted below the bed parallel to its pivotal axis, one end of each spring being held against rotation by adjustable means for applying desired initial tension and the other end extending tangentially as a lever. These levers are pivoted to adjustable link means pivoted to the bed in spaced relation to the pivotal axis, so that the springs are stressed when the bed is swung down and the spring force is exerted to oppose the weight of the bed with an equal power in a manner to provide a counterbalanced condition in any position of the bed out of the vertical. The arrangement is such that the moment of the bed and the moment of the spring force acting thereagainst are practically equal to each other for any position of the bed between its extreme positions, but the bed moment is exceeded by the spring moment when the bed is adjacent its use or stowed positions. The bed is thus perfectly balanced at any point in its swinging movement between the use and stowed positions, at its use position is urged toward the stowed position, and at its stowed position is urged into fully retracted position.

The invention provides several important advantages over prior counterbalance mechanisms, one such advantage being the adjustability of the initial spring tension in accordance with variations in the weight of different beds whether of the same or difierent types. Another advantage is the ready adaptability of the counterbalance mechanism to various styles of beds and to variations in the location of the pivotal axis of the beds. The invention also allows for slight variations in application to individual beds of the same type and nominal dimensions. The counterbalance mechanism is adapted for subassembly as a unit with the bed and bed pocket for application in a desired location in a sleeping car. It is also a feature of the invention that the counterbalance mechanism may easily be disassembled for replacement of WOIH or damaged parts without requiring removal of the bed or mechanism from the car.

It is an object of the present invention to provide a folding bed counterbalance mechanism which just balances the bed in positions between use and stowed positions and at the extreme positions thereof urges the bed from the use position and urges it closed at the stowed position.

It is another object to provide a folding bed counterbalance mechanism by which the weight of the bed in ment is opposed by a practically equal force.

Patented Jan. 29, 1957 Another object is the provision of a spring counterbalancing mechanism for a vertically swingable bed which so equally opposes the weight of the bed at all positions thereof between its extreme positions as to hold the bed in any intermediate position.

A further object is the provision of a torsion spring counterbalance mechanism for a vertically swingable bed including lever linkage between the spring means and bed so arranged that the bed is substantially exactly balanced in any position between its extreme positions and is subjected to a force greater than required to balance it at said extreme positions.

It is still another object of the invention to provide a torsion spring counterbalance mechanism for a bed pivoted to swing vertically between use and stowed positions having lever linkage with the bed so arranged that the moments of the bed and of the spring force about the pivotal axis of the bed are substantially equal and opposed substantially throughout the range of movement of the bed.

Another object is the provision of torsion spring means for counterbalancing a pivoted bed having pivotal lever linkage between the spring means and bed, in which the pivots are so located relative to each other that the spring force substantially exactly balances the bed at any position thereof between its extreme positions and exceeds the force required to balance the bed at the extreme positions.

An important object is the provision of a folding bed counterbalance mechanism adapted for subassembly with the bed and bed pocket structure for application as a unit in a predetermined location.

Other and further objects, advantages, and features of the invention will be apparent to those skilled in the art from the following description and the accompanying drawings, in which:

Fig. l is a front elevational view of a portion of a pivoted bed and one form of counterbalance mechanism according to the invention;

Fig. 2 is a vertical sectional view taken substantially as indicated by the line 22 of Fig. 1;

Fig. 3 is a fragmentary perspective view showing more clearly the relationship of the link means and spring means;

Fig. 4 is a view similar to Fig. 1, but illustrating a somewhat modified form of the invention; and

Fig. 5 is a vertical sectional view taken substantially on the line 5-5 of Fig. 4.

Referring first to Figs. 1 to 3 of the drawings, there is shown a bed B which may be stowed in a vertical position in a bed pocket of a railway sleeping car compartment, the pocket being defined by an end wall E, which may be a portion of a partition defining the compartment, and side walls S extending from the end wall E. A mattress retainer R of known type is pivoted to the end of the bed within the pocket to hold the bedding against displacement in the stowed position. As will be evident particularly from Fig. 1, :the bottom of the bed serves as a closure for the upper portion of the bed pocket, extending substantially across the open end thereof flush with the edges of the side walls S when the bed is in the vertical position. The upper portions of the side walls S may be offset inwardly or formed with flanges so that there are no appreciable gaps at the sides of the bed bottom in the pocket-closing position. A seat, not shown, of a well-known type having a back rest portion pivoted :to the seat portion for swinging downwardly thereover is preferably employed extending across the open end of the bed pocket, with its back rest fixed to the bottom of the bed so as to be swung down:

" between the seat portion and the bed when the bed is 3 moved to horizontal position. The seat conceals from view the lower interior portion of the bed' pocket, the back rest extending upwardly beyond the lower end of the bed when the bed is in vertical stowed position.

A base plate forms the floor of the bed pocket, and has vertical extensions 11 at its side edges which form the lower portions of the side walls S. Angle members 12 may be employed to fasten the base plate and extensions to the end wall E. Adjacent one end, the bed B is pivotally mounted on the vertical bme plate extensions 11 by suitable pivots 13 at its opposite sides, so that it may be swung about a horizontal axis between its vertical stowed position and horizontal use position as shown respectively by solid and dotted lines in Fig. 2, appropriate catch means being employed to secure it at each position. The weight of the bed in such swinging movement is balancedby the counterbalance mechanism of this invention, shown disposed in the bed pocket below .the bed, and comprising a pair of helical torsion springs 15 with the ends tangentially extended to act as levers.

The springs are mounted in axial alignment on a horizontal support arbor or shaft 16 parallel to the pivotal axis of the bed, secured at its ends to :the vertical extensions ll by inverted U-shaped brackets 17 welded. or otherwise fixed to the side walls and having bolts 13 or the like extending across the open ends thereof below the ends of the shaft. The shaft 16 may be a length of pipe, and has an outer diameter smaller than the internal diameter of the springs 15, as clearly'shown in Fig. 2. A pair of collars 19 are mounted on the central portion of the shaft to be fixed at desired locations thereon by screws or the like, and each of the springs 15 is disposed between one of the collars and the adjacent bracket 17 securing one end of the shaft. The collars 19 are omitted from Fig. 2 for clearness. One extended lever end 29 of each spring, in this case the inner end, projects downwardly and rearwardly, or toward the end wall E, into proximity with a suitably braced stop bracket 23 fixed to the base plate 10 and tends to move against the bracket when the spring is stressed. A bolt 22 is threaded through the end 29 to bear against the bracket 21 and adjust the position of the spring end relative there to and thus regulate the initial tension of the spring. A pair of nuts 23 work on the bolt to bear against opposite faces of the spring end for maintaining the desired adjustment. The other end 24 of each spring, which also extends downwardly and rearwardly as a lever, is pivoted to the lower end of an upwardly extending link member 25. Each link member is formed in two parts threadedly connected so that its length may be varied, the lower portion 26 being bifurcated to receive the spring end and the upper portion 27 having a flattened section disposed in a plane transverse of the shaft 16. A suitable pivot 28, such as a bolt, extends through the spring end 24 and the forked end of the portion 26 to provide a hinged connection.

The flattened upper ends of the link members are apertured to extend about a saddle bar 30 of a length corresponding to the width of the bed B and extending parallel to the shaft 16 and to the pivotal axis of the bed. One of the link members is welded as at 31 or otherwise rigidly secured to the bar 30, while the other is not so secured but is held against Shifiting axially of the bar by a pair of collars 32 disposed on opposite sides of the flattened upper end of the link member and fixed pivoted 'by suitable pins, bolts, or the like to opposite sides of the bed on a line parallel to the pivotal axis and lying between that axis and the adjacent end of the bed, and spaced on the bed sides above the level of the pivotal axis. The link elements 33 are of such length as to swing the bar 30 clear of the end of the bed. The link members 25, saddle bar 30, and link elements 33 in effect provide rigid link means pivotally connecting the torsion springs and bed, it being noted that the rigid connection of one of the link members to the bar 30 is sufficient to maintain the link elements 33 and link members 25 in the same plane. To prevent luggage or other articles disuudcr the seat previously referred to from entering the bed pocket and possibly interfering with the counterbalance mechanism, a luggage protection rod 36 extends horizontally across the bed pocket near the floor, somewhat forwardly of the springs 15, and is supported at its ends by brackets 37 secured to the bed plate extensions 11.

in manufacture, the base plate to with its vertical side extensions 11 may be formed to the desired shape, the link elements 33 pivoted to the bed, and the bed pivotal ly mounted on the extensions 11. The U -shaped brackets 17 are secured in place, and the shaft 16 with the springs 15 and collars 19 thereon mounted in the brackets. The saddle bar 30 with the upper portions 27 of the link members 25 secured thereon as described is welded to the link elements 33, and with the bed in the vertical position the lower link member portions 26 are rotated to adjust the length of the link members as desired and then are pivoted to the spring ends as described. The bolts 22 are turned in the spring ends 28 to engage the brackets 21, previously secured to the base plate 16, and impose the desired tension on the springs. The rod 36 may then be applied, and the upper portions of the side walls S secured on the vertical extensions 5.1, when the combined bed pocket, bed, and counterbalance mechanism is ready for application as a unit to the car. The angle members 12 are secured to the extensions it and end wall E, and the upper portions of th side walls may also be suitably joined to the end wall, to fix the unit in place. The order in which the several parts are assembled may of course be varied in accordance with manufactoring convenience, except that preferably the link members 25 are pivoted to the spring ends 24 before initial tensioning of the springs. it will be clear that the mechanism may readily be disassembled for replacement of worn or damaged parts or removal. from the car.

The operation of the counterbalance mechanism is extremely simple, smooth, and effective. As the bed is swung downwardly from the vertical stowed position, the link pivots 35 swing upwardly in an are about the pivotal axis of the bed and the spring ends 24 are drawn by the link means substantially in an are about the axis of shaft 16, stressing the springs and resisting the movement of the bed, the spring torque increasing as the bed moves down. When the bed is in the horizontal use position, the spring torque is at its greatest, and as the bed is swung upwardly so that itsrnoment decreases, the spring torque also decreases as the spring ends swing back toward their lowermost positions. Thus as the moment of the bed including any effect due to the connected seat back portion about its pivotal axis increases or decreases, the opposed moment due to the spring force varies similarly, but this is not to say that the spring moment varies directly with the spring torque. The spring torque is applied to the bed through the link pivots 35 by the link means, and due to the swinging of these pivots about the pivotal axis, the application of the maximum spring torque is not necessarily through the maximum moment arm, as will be evident from Fig. 2. Therefore, by the construction illustrated and described, the spring moment on the bed is caused practically to equal the moment due to the weight of the bed at all positions of the bed intermediate its stowed and use positions, and in combination with the friction of the bed pivots to hold the bed in any desired intermediate position. At the same time, the spring moment in the horizontal use position of the bed exceeds the bed moment so that upon release of the bed it is raised slightly, and at the stowed bed position the spring moment again somewhat exceeds the moment of the bed so that the bed is urged to fully closed position in the bed pocket.

Manipulation of the bed is thus greatly facilitated, for the occupant or a porter may stand directly in the path of the bed when releasing it from the vertical position, draw it part way down, step to one side without having to support the bed at the same time, and complete the moving of the bed to horizontal position. To stow the bed, he need only release it so that it automatically swings upward slightly, then raise it to adjacent the vertical position, move into the space cleared by the bed, and push it fully into the bed pocket, this final movement of the bed being aided by the pushing-to action of the counterbalance mechanism as described. Any resistance to full closing of the bed into the pocket, such as may occur from pillows or other bedding, is largely if not completely overcome by this excess of the spring moment over the bed moment at the stowed position. All danger of injury due to a bed falling because insufliciently counterbalanced is practically eliminated, without requiring exertion to overcome the spring force such as is necessary when a bed is over-counterbalanced. In some sleeping car accommodations, also, the bed in its use position extends over or otherwise hampers use of toilet facilities; by the present invention, the bed may easily be swung out of the way and restored to horizontal position, thus occasioning a minimum of inconvenience. Only slight muscular exertion is required to open and close a bed employing this counterbalance mechanism. The adjusting bolts 22 permit changing of the initial stress on the springs in accordance with variations in the weight of different beds, while the adjustable link members 25 allow for slight variations in dimensions or location of parts, so that the counterbalancing mechanism is readily adaptable to differences in individual parts and of mounting in the case of nominally identical beds assembled with the mechanism.

The invention is furthermore easily adapted to use with differently arranged beds, as will appear from another form of the mechanism illustrated in Figs. 4 and 5, in which the same reference characters are employed to identify parts substantially the same as corresponding parts in the embodiment just described. In the form of the invention shown in Figs. 4 and 5, a base plate 40 with vertical side extensions 41 similar to the base plate 1d and extensions 11 is provided, but fitting snugly be tween the side walls S of the bed pocket, which extend substantially from the floor of the car. The vertical extensions 41 are secured to the side walls by the bed pivot fixtures, which thus hold the base plate and its extensions assembled in the bed pocket. A closure sheet 42 is disposed across the lower open end of the bed pocket, and may have a reinforcing stiffener 43 of suitable cross section adjacent its upper edge. Angle clips 44 are provided to secure the sheet 42 to the side extensions 41 of the base plate. The side walls S may be secured to the car floor and end wall E of the bed pocket in any desired manner. The bed B is mounted on the extensions 41 by pivots 13 to swing into and out of the bed pocket as in the first-described form, but the pivotal axis is located closer to the end of the bed, and while at the same time the axis is disposed nearer the end wall .13 than in the form of Figs. 1 to 3, the end of the bed is spaced farther from the end wall. Since no seat is employed in connection with the bed, the pivotal axis is also located at a lower level than in'the previous embodiment. so that the bed is closer to the car floor when in extended or use position. The height of the closure sheet 42 is such as to come substantially to the lower end of the bed bottom when the bed is in vertical stowed position as ndicated by dotted lines in Fig. 5, so that the bed bottom and sheet 42'provide a substantially flush outer surface for the closed bed pocket. The closure sheet is omitted in Fig. 4 to show the counterbalance mechanism moreclearly. The helical torsion springs 15 are mounted on the shaft 16 and held in place between the collars 19 and shaft-supporting brackets 17 on the extensions 41. The adjusting bolts 22 in the extended lever ends 20 of the springs engage against the stop brackets 21 on the base plate to apply desired initial stress to the springs. The opposite ends 24. of the springs are connected to the bed by links 45 which are similar to the link members 25 but somewhat longer. The lower portions 46 of links 45 are bifurcated and pivoted over the spring ends 24 by bolts 28, and thread on to the lower ends of the upper portions 47 to provide for length adjustment. The upper portions 47 of the links have flattened portions which are pivoted to the end of the bed near its upper edgeby means of brackets 48 each shownas comprising a pair of angle members each having one flange secured to the end of the bed and the other projecting therefrom as a pivot lug. Each link 45 is pivotally secured between a pair of the projecting flanges by a suitable pin 49 or the like. In this embodiment, the links 45 alone serve as the link means pivotally connecting the springs to the bed, affording a simpler construction than provided in the other disclosed embodiment of the invention.

The assembly and application of the bed, bed pocket, and counterbalance -mechanism is substantially as described in connection with the other form of the invention disclosed, and need not be repeated. It may be noted, however, that the use of the links 45 as the link means instead of the link members 25, saddle bar 30, and link elements 33 simplifies the work of assembling the parts. The operation of the bed B of the form of Figs. 4 and 5, and the advantages provided, are substantially the same as explained with regard to the embodiment of Figs. 1 to 3. The bed may be left at any position intermediate its vertical stowed position and horizontal use position by reason of the practically exact counterbalancing provided by the disclosed construction, and adjacent its use and stowed-positions the spring moment is in excess of the bed moment, for the same purposes and with the same results as in the case of the construction of Figs. 1 to 3. This is accomplished even though the two constructions, while similar, differ in the dimensions and spacing involved, or mother words in the points of aplpication of the various forces, and indicates the adaptability of the invention to varying specific structures and arrangements.

The slight raising of the bed by the spring force when released from its horizontal position, in addition to facilitating its manual raising to vertical position, serves as a positive indication that it has been freed. The counterbalance force urging the bed to fully closed condition when it comes to the vertical position also provides a safety factor to prevent accidental downward swinging of the bed upon release of the catch means, whether intentional or inadvertent. In the arrangement of Figs. 1 to 3, the bed is intended for use in a somewhat more limited space than that which is to be provided for the bed employed in the construction of Figs. 4- and 5, and

accordingly it is so mounted as to extend as far as possible into the bed pocket when in horizontal position. The bed of the Figs. 4 and 5 arrangement is mounted to have practically its entire length outside of the pocket when in use position, space limitation being less of a factor in this case. The mattress retainer R, it will be apparent. divides the upper bed-receiving portion of the pocket from the lower portion in which the counterbalance mechanism is mounted.

' The invention is adaptable and applicable to any foldable or vertically swinging bed, and is not limited to use with beds, but may be employed in a variety of fields whenever it is desired so to counterbalance a vertically swingable member or device that it may safely be held -in an intermediate position by the inventive mechanism,

enemas i that it may be urged out of one extreme position, or that it may be urged into the other extreme position-in short, whenever any or all of the advantages obtained with a bed are desired for a similarly pivoted device.

What is claimed is:

1. counterbalance mechanism for a bed pivoted adjacent one end to swing vertically between a horizontal use position and a ver 'cal stowed position mainly above the pivotal axis thereof, comprising a plurality of helical torsion springs each mounted below the bed parallel to said pivotal axis, means for holding an end of each spring against rotation, lever members rigid with the other ends of the springs, and link means pivoted to the lever members and also pivoted to the bed on a line parallel to and spaced from the pivotal axis inthe direction of said one end of the bed for rotating the lever member, to stress the springs upon downward swinging of the bed and to apply the force of the stressed springs to the bed upon upward swinging thereof, the several pivots being relatively located to result in a moment about the pivotal axis due to the spring force opposed to and greater than the moment due to the weight of the bed when the bed is disposed adjacent either of its said positions and substantially equal to the weight-caused moment when the bed is disposed at any other point between its said positions.

2. counterbalance mechanism for a bed pivoted adjacent one end to swing vertically between a horizontal use position and a vertical stowed position, comprising torsion spring means mounted below the bed parallel to the pivotal axis of the bed, means for holding at least one portion of the spring means against rotation while permitting rotation of at least one portion integral with a non-rotatable portion, lever means rigid with each rotatable portion of the spring means, and link means pivoted to the lever means and also pivoted to the bed on a line parallel to and spaced from the pivotal axis in the direction of said one end of the bed for rotating the lever means to stress the spring means upon downward swinging of the bed and to apply the force of the stressed spring means to the bed upon upward swinging thereof, the several pivots being relatively located to produce a moment about said pivotal axis due to the spring force opposed to and greater than the moment due to the weight of the bed with the bed adjacent either of its said positions and substantially equal to the weight-caused moment with the bed at any other point between its said positions.

3. Counterbalance mechanism for a bed pivoted adjacent one end to swing vertically between a horizontal use position and a vertical stowed position, comprising torsion spring means mounted below the bed parallel to the pivotal axis of the bed, means for holding at least one portion of the spring means against rotation while permitting rotation of at least one portion integral with a non-rotatable portion, lever means rigid with each rotatable portion of the spring means, and link means pivoted to the lever means and also pivoted to the bed on a line parallel to and spaced from the pivotal axis in the direction of said one end of the bed for rotating the lever means to stress the spring means upon downward swinging of the bed and to apply the force of the stressed spring means to the bed upon upward swinging thereof, the several pivots being relatively located to produce a moment about said pivotal. axis due to the spring force opposed and substantially equal to the moment due to the weight of the bed at substantially all positions of the bed between its said use and stowed positions.

4. Counterbalance mechanism for a bed pivoted adjacent one end to swing vertically between a horizontal use position and a vertical stowed position, comprising torsion spring means mounted below the bed parallel to the pivotal axis of the bed, means for holding at least non-rotatable portion, lever means rigid with each rotatable portion of the spring means, and link means pivoted to the lever means and also pivoted to the bed on a line parallel to and spaced from the pivotal axis in the direction of said one end of the bed for rotating the lever means to stress the spring means upon downward swinging of the bed and to apply the force of the stressed spring means to the bed upon upward swinging thereof, the several pivots being relatively located to produce a moment about said pivotal axis due to the spring force opposed to and greater than the moment due to the weight of the bed when the bed is disposed adjacent either of its said positions.

5. counterbalance mechanism for a bed pivoted to swing vertically between a horizontal use position and a stowed position, comprising torsion spring means arranged parallel to the pivotal axis of the bed and including at least one non-rotatable portion and at least one rotatable portion operatively joined with each non-rotatable portion, lever means rigid with each rotatable portion, and link means pivoted to the lever means and to the bed for rotating the lever means to stress the spring means upon downward swinging of the bed and to apply the force of the stressed spring means to the bed upon upward swinging thereof for opposing the moment due to the weight of the bed about the pivotal axis by a spring-caused moment greater than the weight-caused moment when the bed is disposed adjacent either of its said positions and substantially equal to the weightcaused moment when the bed is disposed in any other position between its said use and stowed positions.

6. Counterbalance mechanism for a bed pivoted to swing vertically between a horizontal use position and a stowed position, comprising torsion spring means arranged parallel to the pivotal axis of the bed and including at least one non-rotatable portion and at least one rotatable portion operatively joined with each non-rotatable portion, lever means rigid with each rotatable portion, and link means pivoted to the lever means and to the bed for rotating the lever means to stress the spring means upon downward swinging of the bed and to apply the force of the stressed spring means to the bed upon upward swinging thereof for opposing the moment due to the weight of the bed about the pivotal axis by a spring-caused moment substantially equal to the weightcaused moment at substantially all positions of the bed between its said use and stowed positions.

7. counterbalance mechanism for a bed pivoted to swing vertically between a horizontal use position and a stowed position, comprising torsion spring means arranged parallel to the pivotal axis of the bed and including at least one non-rotatable portion and at least one rotatable portion operatively joined with each non-rotatable portion, lever means rigid with each rotatable portion, and link means pivoted to the lever means and to the bed for rotating the lever means to stress the spring means upon downward swinging of the bed and to apply the force of the stressed spring means to the bed upon upward swinging thereof for opposing the moment due to the weight of the bed about the pivotal axis by a springcaused moment greater than the weight-caused moment when the bed is disposed adjacent either of its said positions.

8. Counterbalance mechanism for a bed pivoted adjacent one end to swing vertically between a horizontal use position and a stowed position, comprising torsion spring means arranged parallel to the pivotal axis of the bed, adjustable means for anchoring at least one portion of the spring means against rotation and imposing initial stress thereon, the spring means having at least one rotatable portion operatively joined with each anchored portion, lever means rigid with each rotatable portion, a pair of parallel link elements of a length to extend beyond the bounding surfaces of said one end of the bed and each pivoted to the bed between said one end and the pivotal axis, a cross bar rigid with and connecting the link elements, and at least one link member rigid with said cross bar extending in substantially the plane of the link elements and pivoted to said lever means, said link elements, cross bar, and link member providing rigid link means pivotally connecting tte bed and lever means for rotating the lever means to stress the spring means upon downward swinging of the bed and to apply the force of the stressed spring means to the bed upon upward swinging thereof.

9. Counterbalance mechanism for a bed pivoted ad jacent one end to swing vertically between a horizontal use position and a stowed position, comprising torsion spring means arranged parallel to the pivotal axis of the bed and having operatively joined anchored and rotatable portions, lever means rigid with each rotatable portion, a pair of parallel link elements each pivoted to the bed between said one end and the pivotal axis, a cross bar rigid with and connecting the link elements, and at least one link member rigid with the cross bar extending in substantially the plane of the link elements and pivoted to the lever means, said link elements, cross bar, and link member providing rigid link means pivotally connecting the bed and lever means for rotating the lever means to stress the spring means upon downward swinging of the bed and to apply the force of the stressed spring means to the bed upon upward swinging thereof.

10. A counterbalanced pivoted device subassembly for application as a unit in a pocket for said device partially defined by a pair of side wall members, comprising a base plate having a length substantially the same as the distance between the side wall members, parallel vertical side extensions secured to the ends of the base plate and adapted for securement to said side wall members, a device pivoted adjacent one end on said extensions to swing vertically between the planes thereof, horizontal torsion spring means mounted on said extensions below the device, means on said base plate to hold a portion of the spring means against rotation, the spring means having a rotatable portion operatively joined with a nonrotating portion, lever means rigid with a rotatable portion, and link means pivotally connecting the lever means and the device.

References Cited in the file of this patent UNITED STATES PATENTS Wright June 27, 1933 

